1. Field of the Invention
The present invention relates to a method for authenticating a charge-coupled device (CCD), in particular in a digital camera, a device for authenticating a charge-coupled device (CCD), and a corresponding digital CCD camera.
2. Description of the Related Art
Different methods for identifying products as described, for example, in the document “Physical One-Way Functions” by Pappu Srinivasa Ravikanth are already known. In this document the author describes the possibility of basing a cryptography structure on algorithmic one-way functions. These so-called one-way functions are numeric functions and may be viewed in a broader sense as the physical implementation of the encoding method.
Most known methods for identifying and authenticating products are based on the addition of an unclonable module to the product to be identified and authenticated. The product is identified and authenticated by reading out a value specified by the unclonable module. The general approach of using so-called physical unclonable functions to prevent cloning is to generate a module having a specific and unclonable random value or to find a randomly distributed intrinsic property of the module which is to be authenticated.
Three main disadvantages of the addition of a new module are that there are extra costs for the new module, the module must be selected in such a way that allows for the working conditions of the product or device to be identified, and if the product or device to be identified is to be identified during an operating time of the product or device, e.g., every time the corresponding system is started, the content of the module remains readable during or immediately before start-up of the product or device to be identified. This reading requires additional hardware that may be expensive and must be implemented for every product or device to be identified. Such requirements must be fulfilled, for example, when identifying and authenticating a digital CCD camera or the CCD chip implemented therein.
Accordingly, it would be desirable to provide an alternative option for identifying and authenticating a product or device, particularly a digital CCD camera, smoothly, preferably at any time, and as cost-effectively as possible.